President Barack Obama Wednesday acknowledged the failure of the federal government’s economic policies over the last 50 years to help Africans-Americans catch up with whites economically, but he still urged Americans to rally for a political fix to the economy.

Since 1963, the economic gap “has not lessened, it has grown,” Obama declared in a speech marking the 50th anniversary of Rev. Martin Luther King’s famous “content of their character” speech.

Americans’ wages have stagnated “even as corporate profits soar, even as the pay of a fortunate few explodes. Inequality has steadily risen over the decades. Upward mobility has become harder,” Obama said, while standing on the steps of the Lincoln Monument before tens of thousands.

Instead of lauding entrepreneurship, personal ambition, families and technological advances, Obama declared “the promise of this nation will only be kept when we work together.”

“Change has always been built on our willingness, We The People, to take on the mantle of citizenship,” he said later.

“That’s the lesson of our past,” said Obama.

Since Obama’s inauguration in 2009, he has worked to expand government’s role in the nation’s education, banking, real estate, manufacturing, health-care and energy sectors.

At the same time, the richest one percent of Americans doubled their income from 2009 to 2011, while all other Americans saw a slight drop in their income.

Households’ after-inflation income dropped by 4.4 percent, or $1,002, after the recession ended in June 2010, according to a recent report by Sentier Research.

The lousy economic numbers were highlighted by an August report from the Pew center.

Since 1963, the gap between whites’ and blacks’ median household income has grown by 50 percent to $27,414 and the median household wealth gap has expanded by 10 percent to $84,960, partly because fewer blacks than whites are getting married, said the Aug. 22 report, titled “King’s Dream Remains an Elusive Goal; Many Americans See Racial Disparities.”

Obama, however, denounced conservatives who believe government played a role in slowing African-Americans’ progress.

The “politics of division” push “a great untruth — that government was somehow to blame for their growing economic insecurity,” he complained.

Also, “technology and global competition have subtracted those jobs that once provided a foothold into the middle class — reduced the bargaining power of American workers,” he said.